1. Field of the Invention
The present invention relates in general to tire-building machines and more particularly to a mechanism for installation and removal of a green tire forming drum in a tire-building machine.
2. Description of the Prior Art
Generally, a green tire forming drum, which is to be installed on a spindle of a tire-building machine, is of such weight that it ranges from about several hundred kilograms up to several tons. In case of placing bead bundles in position during tire construction, the drum is subjected to several tons of external force directed axially thereof. For this reason, the drum needs to be firmly and rigidly attached to the spindle of the tire-building machine. To this end, it has been common to fasten them with a number of fastening bolts, for example three to eight bolts. During installation, the drum is lifted by a crane and held next to the spindle while being axially aligned with same, after which both are fastened together with the above described fastening bolts.
A disadvantage of the prior art drum installing mechanism is that in installation of the drum each fastening bolts need to be tightened uniformly, i.e. with the same torque, resulting in the necessity of a delicate, difficult and time-consuming installation work. Further, irregularity in tightening of the fastening bolts may possibly deteriorate the concentricity between the drum and the spindle and cause vibrations of the drum during rotation of same, leading to deterioration in the quantity of the tire.